This invention relates to hybrid circuit manufacturing techniques and more particularly to a pneumatic diverter for moving screened substrates in thick film printers.
In the manufacture of hybrid circuits, the practice is to locate a ceramic substrate on the platen of a table in a thick film screen printer, the table then moving forward where a layer of resistive, conductive, electrical or protective material, for example, is screened on the substrate. As the table moves rearward, the screened substrate is wiped off of the platen and onto a horizontally positioned chute of the printer. As the table again moves into position for screening the next substrate, the chute automatically tilts and the previously screened substrate slides directly onto a conveyor belt. Since such equipment normally places screened substrates in a straight line on the belt, the speed at which the conveyor may operate limits the speed at which the printer can operate without it depositing screened substrates on top of each other on the belt. A prior-art method for increasing the speed at which the printer may operate, without changing the speed of the conveyor, is to periodically mechanically move the chute sideways before it is tilted in order to place screened substrates adjacent opposite sides of the belt. This technique is relatively complex and cumbersome. Also, since substrates are made of ceramic, fine particles of highly abrasive material are continually deposited on the chute. They may cause fouling of and excessive wear in parts of such a mechanical structure.
An object of this invention is the provision of a diverter for substrates in thick film screen printers which is relatively simple and free of fouling and wear.